OSHA Scaffolding Safety – 29 CFR 1926.451

Scaffolds provide temporary elevated work platforms for construction, maintenance, repair, painting, and many other activities. Although scaffolds provide access to areas that may otherwise be difficult to reach, employees can be seriously injured when scaffolds are improperly erected, overloaded, damaged, inadequately protected, or used incorrectly.

Common scaffold hazards include falls from elevated platforms, scaffold collapse, falling objects, unstable foundations, inadequate access, electrical hazards, and improper use.

OSHA scaffolding requirements are primarily found in 29 CFR 1926 Subpart L – Scaffolds. Section 1926.451 establishes general requirements for scaffold capacity, platforms, access, use, fall protection, and falling-object protection.

Types of Scaffolds

Scaffolds come in many configurations depending on the work being performed.

Two broad categories are:

Supported Scaffolds
Supported scaffolds consist of platforms supported by rigid structural members such as poles, legs, frames, posts, or outriggers. Examples include frame scaffolds, tube-and-coupler scaffolds, mobile scaffolds, and pole scaffolds.

Suspension Scaffolds
Suspension scaffolds consist of platforms suspended by ropes or other non-rigid means from an overhead structure. Examples include single-point and two-point adjustable suspension scaffolds commonly used for exterior building work.

Specialty scaffolds may have additional OSHA requirements depending on their design and use.

Scaffold Capacity

Scaffolds must be capable of supporting the loads placed on them.

Under OSHA’s general scaffold requirements, each scaffold and scaffold component must generally be capable of supporting, without failure, its own weight and at least four times the maximum intended load applied or transmitted to it.

Scaffolds must be designed by a qualified person and constructed and loaded in accordance with that design.

Employees should never overload a scaffold with workers, tools, equipment, or materials.

Falls From Scaffolds

Falls are one of the most serious scaffold hazards.

For construction scaffolds, OSHA generally requires each employee on a scaffold more than 10 feet above a lower level to be protected from falling.

The required protection depends on the type of scaffold. Depending on the situation, OSHA may require:

• Guardrail systems.
• Personal fall arrest systems.
• Both guardrails and personal fall arrest systems.

For example, employees working from single-point or two-point adjustable suspension scaffolds generally require both a personal fall arrest system and a guardrail system.

The fall-protection system must be appropriate for the particular scaffold and work being performed.

Scaffold Stability

Scaffolds must remain stable while supporting employees, tools, materials, and other loads.

The condition of the ground or supporting surface can significantly affect scaffold stability. Soft soil, uneven surfaces, settling, inadequate foundations, or improper support can cause a scaffold to shift, lean, or collapse.

Supported scaffold poles, legs, posts, frames, and uprights must be plumb and braced to prevent swaying and displacement.

As scaffolds become taller or conditions require additional stability, ties, guys, braces, outriggers, or other appropriate methods may be necessary.

Platforms and Planking

Scaffold platforms provide the walking and working surface for employees and must be properly constructed.

OSHA generally requires working levels to be fully planked or decked between the front uprights and guardrail supports.

Gaps between adjacent platform units and between platforms and uprights generally cannot exceed 1 inch, except where OSHA permits additional space because of the scaffold configuration or work being performed.

Damaged planks, inadequate support, excessive gaps, improperly positioned platforms, and unsecured components can contribute to falls and scaffold failures.

Platforms must also be capable of supporting the intended load.

Safe Access to Scaffolds

Employees must have safe access to scaffold platforms.

When scaffold platforms are more than 2 feet above or below a point of access, OSHA requires an appropriate means of access such as:

• Portable ladders.
• Hook-on or attachable ladders.
• Stair towers.
• Stairway-type ladders.
• Ramps or walkways.
• Integral prefabricated scaffold access.
• Direct access from another scaffold, structure, or similar surface.

Cross braces should not be used as a means of scaffold access.

Employees should not climb scaffold components unless those components are specifically designed and constructed for climbing.

Falling Objects

Scaffolds can expose employees working below to tools, materials, equipment, and debris falling from elevated platforms.

Employees on scaffolds must wear hard hats and, when falling-object hazards exist, additional protection may be necessary.

Depending on the conditions, protection can include:

• Toeboards.
• Screens or panels.
• Guardrail systems.
• Debris nets.
• Catch platforms.
• Canopy structures.
• Barricades or restricted access below the scaffold.

Materials and equipment should be stored and handled so they do not create unnecessary falling-object hazards.

Mobile Scaffolds

Mobile scaffolds allow elevated work platforms to be moved as work progresses, but their mobility creates additional hazards.

Floor conditions, scaffold height, casters, outriggers, overhead obstructions, employees, and materials can all affect stability.

Casters and wheels must be properly secured against movement when the scaffold is being used.

Employees generally should not remain on scaffolds while they are being moved unless the scaffold and movement comply with OSHA’s specific requirements for mobile scaffolds.

Scaffolds and Electrical Hazards

Scaffolds are frequently erected near buildings, utilities, and electrical equipment. Metal scaffold components and conductive materials can create a serious electrocution hazard if they contact energized electrical lines.

OSHA establishes minimum clearances between scaffolds and exposed energized power lines. In many common situations involving uninsulated lines of less than 50 kV, the minimum clearance is 10 feet.

Required clearance depends on line voltage and whether the line is insulated or uninsulated.

Electrical hazards should be evaluated before scaffolds are erected, moved, altered, used, or dismantled.

Scaffold Inspections

OSHA requires scaffolds and scaffold components to be inspected for visible defects by a competent person before each work shift and after any occurrence that could affect the scaffold’s structural integrity.

Inspection should address conditions such as:

• Damaged or weakened components.
• Missing or inadequate bracing.
• Unstable foundations or supports.
• Damaged or displaced planking.
• Missing guardrails.
• Unsafe access.
• Improper ties or anchorage.
• Excessive loading.
• Electrical hazards.
• Conditions resulting from weather, impact, alteration, or movement.

Damaged or weakened scaffold components must be repaired, replaced, adequately braced, or removed from service as required.

The Scaffold Competent Person

A competent person has an important role in scaffold safety.

Under OSHA, a competent person is capable of identifying existing and predictable hazards in the surroundings or working conditions and has authorization to take prompt corrective measures to eliminate them.

Among other responsibilities, competent persons perform required scaffold inspections and supervise and direct scaffold erection, movement, dismantling, and alteration.

Employees performing those activities must also be experienced and trained for the work and selected by the competent person.

Weather and Scaffold Safety

Weather can significantly affect scaffold safety.

Employees generally may not work on scaffolds covered with snow, ice, or other slippery material except as necessary to remove those conditions.

Work on or from scaffolds during storms or high winds is prohibited unless a competent person determines that it is safe and OSHA’s required protective measures are provided.

Wind can also affect scaffold stability, materials stored on platforms, suspended scaffolds, and the safe handling of large or lightweight objects.

Why Scaffold Safety Matters

Safe scaffold use depends on more than the platform itself. The foundation, structural components, bracing, platforms, access, fall protection, electrical clearances, surrounding conditions, and loads placed on the scaffold all work together as a system.

Before employees use a scaffold, employers should ensure that it is properly designed and erected, capable of supporting the intended load, provided with safe access and required fall protection, and inspected by a competent person.

For additional regulatory information, see OSHA 29 CFR 1926.451 – General Requirements for Scaffolds and 29 CFR 1926 Subpart L – Scaffolds.

For company-specific requirements covering scaffold erection, inspections, competent persons, fall protection, access, training, and safe-work procedures, refer to the company’s Scaffolding Safety Program.